/Engine/Source/Runtime/Datasmith/CADKernel/Public/CADKernel/Geo/Sampling/PolylineTools.h
Project a Set of points on a restricted polyline (StartIndex & EndIndex define the polyline boundary) the points are projected on all segments of the polyline, the closest are selected
double ProjectPointToPolyline ( int32 BoundaryIndices, const PointType & InPointToProject, PointType & OutProjectedPoint ) const